From: Gao Xiang hsiangkao@linux.alibaba.com
stable inclusion from stable-v5.10.137 commit 0ca556256fb438bb754936e9ec210dc1b26b622f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 448b5a1548d87c246c3d0c3df8480d3c6eb6c11a ]
Currently, vmap()s are avoided if physical addresses are consecutive for decompressed buffers.
I observed that is very common for 4KiB pclusters since the numbers of decompressed pages are almost 2 or 3.
However, such detection doesn't work for Highmem pages on 32-bit machines, let's fix it now.
Reported-by: Liu Jinbao liujinbao1@xiaomi.com Fixes: 7fc45dbc938a ("staging: erofs: introduce generic decompression backend") Link: https://lore.kernel.org/r/20220708101001.21242-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- fs/erofs/decompressor.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 8a6260aac26c..f921580b56cb 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -56,14 +56,18 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
if (page) { __clear_bit(j, bounced); - if (kaddr) { - if (kaddr + PAGE_SIZE == page_address(page)) + if (!PageHighMem(page)) { + if (!i) { + kaddr = page_address(page); + continue; + } + if (kaddr && + kaddr + PAGE_SIZE == page_address(page)) { kaddr += PAGE_SIZE; - else - kaddr = NULL; - } else if (!i) { - kaddr = page_address(page); + continue; + } } + kaddr = NULL; continue; } kaddr = NULL;